The invention concerns an internal combustion engine including a cylinder head having a cylinder head base, a cylinder wall, and a piston which is movable along a cylinder axis and which has a piston crown. A main combustion chamber is formed between the cylinder head base, the cylinder wall, and the piston crown. A pre-chamber is fitted into a bore in the cylinder head and is fixed relative to the bore in the peripheral direction of the bore, and the axis of the bore is at least substantially parallel to the cylinder axis and a pre-chamber combustion chamber is formed in the pre-chamber. At least one ring of transfer openings connects the pre-chamber combustion chamber to the main combustion chamber.
So-called pre-chamber-ignition internal combustion engines of the above-described kind are sufficiently known. Ignition flares issuing from the transfer openings serve to reliably ignite a mixture in the main combustion chamber.
In many pre-chambers known at the present time, it is not possible to predetermine the exact installation position as the pre-chambers are screwed in place and the precise angular position in the peripheral direction relative to the bore in the cylinder head cannot be established by way of a screwthread. However, internal combustion engines of the general kind set forth are already known, in which the pre-chamber is fixed relative to the bore in the cylinder head in the peripheral direction of the bore (see for example DE 37 09 976 A1).
Internal combustion engines of the general kind set forth suffer from a problem that the ignition flares do not optimally involve the volume of the main combustion chamber, and thus rapid combustion is not guaranteed. If the attempt is made to make the ignition flares larger in size, that also entails a severe thermal loading on the cylinder head base and the piston crown.